The present invention relates generally to agricultural vehicles and particularly to a self-driven forage harvester having a main vehicle and a trailer operatively connected thereto, the trailer being the type which includes auxiliary means for discharge of material in the form of an inclined scraper floor which is rearwardly inclined ascending to an upper discharge end at the rear of the trailer.
The tractive or motive power of self-driven forage harvesters is to a great extent limited due to the power which must be provided for driving the implements or auxiliary equipment operatively associated with the harvester. As a result, self-driven forage harvesters cannot normally be utilized as towing vehicles or tractors if the dimensions and size characteristics of the device are to be maintained within economical limitations. Accordingly, considering the various terrains over which such agricultural devices must travel, the use of known, conventional forage harvesters is rather limited.
Known self-driven forage harvesters of this type normally include a hopper which is arranged on the chassis of the vehicle at a location above the driving axle. Such harvesters also include an inclined scraper floor which ascends rearwardly to an upper container at the end of the vehicle. The scraper floor includes an overhanging discharge end by means of which a subadjacent vehicle may be loaded from the forage harvester.
However, the scraper floor which is usually driven by the same hydraulic engine which drives the vehicle, cannot for the most part be operated if the forage harvester is moving because under such circumstances the major portion of the available driving power is required to propel the forage harvester.
Moreover, if operational problems develop in the discharge device, the entire forage harvester unit will usually break down.
Further disadvantages relate to the fact that the overall mechanism, including the hopper which is arranged thereon, has a relatively high center of gravity. Thus, the forage harvester will be rather difficult to maneuver in rough terrain. Wheel grip will vary with differing loads and tractive power will be lost due to slippage thereby causing further disadvantageous operating features.
It is therefore a primary objective of the present invention to provide a self-driven forage harvester which will exhibit improved driving characteristics and wherein changing load conditions will have a significantly lesser effect upon the driving characteristics of the vehicle.